While the field of rapid prototyping of three dimensional objects has recently seen substantial growth, a number of challenges still remain. First, a new methodology is needed which will allow a rapid prototyping of heterogeneous (physically and/or chemically) parts for specific functional devices. Second, a parallel process (such as a robust layer-by-layer process, in contrast to a point-by-point process) needs to be developed to gain speed for the prototyping. Third, non-planar fabrication technologies are required that will speed the prototyping process and enable the design and fabrication of high aspect ratio and complex macro/micro structures.
Currently, there are a number of rapid protoyping processes under development. Stereolithography (SLA) was the first commercialized, solid, free form fabrication process. It created plastic models directly from liquid photo-curable polymers by a scanning laser beam in a point-by-point fashion onto the polymer to selectively cure the illuminated points in accord with an image of the desired device. Laminated Object Manufacturing (LOM) employs a laser to cut laminated materials and subsequently stacks the cut materials to form a 3D object. Currently the LOM material has very limited composition control.
3-D Printing (3DP), developed at MIT, builds 3D parts by selective deposition of molten wax droplets onto planar powder layers, with the wax acting to bind the powder at the deposition points. Thus, while 3DP printing works for building homogeneous and inhomogeneous parts, it is based on a point-by-point serial deposition process that limits its speed and accuracy.
Selective Laser Sintering (SLS), developed at the University of Texas at Austin, fuses powders to form 2D layers by a point-by-point scan of a laser beeam. Mask and Deposition (MD) developed at Carnegie Mellon University is a thermal spray deposition process which directly builds three-dimensional multi-material structures of arbitrary geometric complexity. However, a large number of masks are required.
The relatively new Direct Photo Shaping process developed at SRI, Inc. is based on layer-by-layer photocuring of a mixture of ceramic slurries and photo sensitive monomers. This method provides a way of maskless rapid prototyping of homogeneous parts.
Each of the above-noted technologies is based on either a planar or layer-by-layer buildup of a material to form a 3D object. All of these processes are limited to fabrication of either homogeneous (i.e., single phase) parts or low speed point-by-point fabrication. Versatile rapid prototyping with desired chemical/physical gradients cannot be realized with the present technologies. A practical non-planar approach for ultra-fast prototyping of functional devices has not yet been developed.
Accordingly, it is an object of this invention to provide a non-planar approach for ultra-fast prototyping of functional devices.
It is another object or this invention to provide a rapid prototyping process that enables construction of a three dimensional object comprised of heterogeneous materials.